1. Field of the Invention
The present invention relates to an image processing apparatus. In particular, the invention relates to an image processing apparatus and a method for processing an image stream having a hierarchical structure.
2. Description of the Related Art
In recent years, the prevalence of infrastructures such as DVD media, digital broadcasting, and on-demand communications over networks has yielded widespread use of digital contents. Since digital contents causes no degradation in quality even after duplication, copyright management is of high importance. Demands for legitimate protection of copyrights on digital contents and other copyrighted materials are expected to grow in the future. Japanese Patent Laid-Open Publication No. 2001-86444 discloses a technique for prohibiting duplication by using copy control information included in a stream.
Nevertheless, techniques like this are no more than a uniform approach of either permitting or prohibiting, and it is impossible to satisfy various levels of demands both from contents providers and from users. For example, the contents providers might let business opportunities slip away if they simply prohibit duplication. Besides, the users have various orientations ranging from high-end to price-sensitive.